Elastic–viscoplastic behavior of plain-woven GFRP laminates: Homogenization using a reduced domain of analysis

In this study, a method for reducing the domain of analysis is developed for the homogenization analysis of plain-woven laminates. To this end, it is first shown that the internal structures of plain-woven laminates satisfy point-symmetry on the assumption that the laminates have the in-phase or out-of-phase laminate configuration of plain fabrics. The point-symmetry is then utilized for the boundary condition of unit cell problems, reducing the domain of analysis to 1/4 and 1/8 for the in-phase and out-of-phase laminate configurations, respectively. Using the present method, the in-plane elastic–viscoplastic deformation of plain-woven GFRP laminates is analyzed based on the homogenization theory of nonlinear time-dependent composites. Moreover, the in-plane uniaxial tensile tests of a plain-woven GFRP laminate at a constant strain rate are performed at a room temperature. It is thus shown that the present analysis successfully predicts the in-plane elastic–viscoplastic behavior of plain-woven GFRP laminates. It is also shown that the laminate configurations of plain fabrics exert an influence on the viscoplastic behavior of laminates, not their elastic behavior.